Electronic equipment like base station transceivers, servers and routers are normally rack mounted in cabinets when in operation. To cope with the heat dissipation from the electronic circuits, cooling of the equipment is necessary. The heat can be transported from the electronic equipment by using air or a fluid and natural convection cooling or forced cooling. Natural air convection cooling is based on the motion caused by the density differences in the air due to a temperature difference. A gas expands when heated and becomes less dense. In a gravitational field, this lighter gas rises and initiates a motion in the gas called natural convection currents. Forced cooling on the other hand involves additional cooling equipment such as fans for increasing the motion of the air flow.
Cabinets using air cooling are often provided with openings in order to allow cooler air outside the cabinet to pass through the cabinet as to cool the electronic equipment. An example is shown in US patent application 2010/0311316 wherein an enclosure 121 for electronic equipment is illustrated having an air inlet vent 122 in the lower part of the enclosure to allow air 123 to enter the enclosure, and a further air vent 124 at the upper part to allow air to exit the enclosure.
The air flow can be forced by fans within the cabinet or by external fans as illustrated in said application. The cabinet shown in US patent application 2010/0311316 is located in an indoor environment.
A disadvantage of using this type of cabinet in an outdoor environment is the increased risk for contamination of the electronic equipment located within the cabinet. Another disadvantage is that the interior can become too cold during very cold weather conditions which mean that additional heater equipment is needed in order to keep the temperature within the specified operational range.